Display testing device



FIG. 1 is a perspective view of the front of a display testing device, according to a first embodiment of the invention;

FIG. 2 is a bottom view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a back view thereof;

FIG. 7 is a perspective view of the front of a display testing device, according to a second embodiment of the invention;

FIG. 8 is a bottom view thereof;

FIG. 9 is a top view thereof;

FIG. 10 is a right side view thereof;

FIG. 11 is a front view thereof; and,

FIG. 12 is a back view thereof. 

The ornamental design for a display testing device, as shown and described. 